More particularly, the invention relates to a machine comprising a casing, an orbiting rotor, and a vane member.
The present invention provides a rotary positive displacement machine comprising:
a casing having a circular cylindrical internal surface delimiting an operating chamber,
a rotor in the operating chamber, the rotor being mounted so as to orbit about a chamber axis which is the axis of the said internal surface, the rotor having a circular cylindrical external surface, the chamber axis passing through the rotor, a generatrix of the external surface being adjacent to the said internal surface, and a diametrically opposite generatrix being spaced from the said internal surface;
a vane member mounted on the casing and being pivotable about a pivot axis parallel to the chamber axis, the vane member being accommodated in a fluid inlet/outlet aperture in the casing, the vane member having a passageway communicating between the exterior of the casing and the operating chamber, the vane member having an arcuate face which is coaxial with the said pivot axis and which has a length substantially equal to that of the rotor, the vane member having end faces extending from the respective lateral ends of the arcuate face towards the pivot axis, and the vane member having a tip face adjacent the rotor, the said faces being sealing faces with respect to corresponding surfaces of the casing aperture and the rotor; and
a linkage which connects the vane member to the rotor so as to keep the tip face of the vane member in sealing contact with the external surface of the rotor, the linkage being connected to the vane member by an articulation having an articulation axis such that a plane containing the articulation axis and the axis of the said external surface passes through the region of sealing contact.